INTRODUCING BULK MATERIALS INTO PNEUMATIC CONVEYING LINES WITH SCREW FEEDERS

The article starts with a presentation of the problems of introducing solids into a pneumatic pressure-operated conveying system. After a comparison of familiar design variants of screw feeders the operating characteristics of such systems are analyzed using a special model, the CPAG-X pump, by way of example. The functional principles and the influencing variables and dependent factors which determine the feeder throughput and drive power required are discussed against the background of a theoretical computational model based on systematic measurements. The basic features of the model are described. It is apparent that screw feeders still have considerable potential for development. For example, the power consumption of a feeder can be reduced by about 30 % by suitable longitudinal grooving of the cylinder liner.